Field of the Invention
Embodiments of the present invention relate generally to image processing and, more specifically, to a technique for deblurring images.
Description of the Related Art
Interest in digital photography has risen dramatically over the past decade due, in part, to the incorporation of digital video cameras into cell phones and other portable computing devices. However, handheld “point and shoot” cameras, such as those found in these portable devices, oftentimes produce images that are blurry. Some existing methods try to estimate the amount and type of the blur and invert the blurring process, but such blind deconvolution approaches are often unstable. Another existing solution to this problem that can be more robust is to capture two images, the intended image (a long exposure) and a short exposure, and if the intended image is blurred, to then deblur the long exposure based on the short exposure. Even if the short exposure is noisy it can provide useful guidance for unblurring the longer, blurry but otherwise better exposure.
The above approach provides reasonable results when the source of the blurriness is camera motion. However, blurriness is often caused by multiple unrelated factors. In particular, objects within the field of view of the camera may be moving, while, simultaneously, the camera itself may be moving. If the deblurring method assumes that the whole image is blurred the same way, the results will be disappointing. Existing approaches fail to distinguish one type of motion from another and therefore cannot deblur a majority of images effectively.
Accordingly, what is needed in the art is an improved technique for deblurring an image that is blurry due to different types of motion.